Identity of the native South American armored scale insect species (Hemiptera: Coccomorpha: Diaspididae) widely misidentified as the North American species Diaspidiotus ancylus Putnam.

Abstract

The Putnam scale, Diaspidiotus ancylus Putnam, 1878 (Hemiptera: Coccomorpha: Diaspididae), a species considered to be native to North America, has frequently been reported to be present in Chile and Argentina, attacking a wide variety of orchard crops (apples, pears, olives, nectarines, grapes) and common street trees (poplar, locust). However, diagnostic DNA sequences from Chilean populations identified as D. ancylus differ from those of North American D. ancylus; instead they are identical to those reported for Clavaspis patagonensis Schneider, Claps, Wei, Normark & Normark, 2020, a species previously known only from a single locality in Argentina. We have examined the Chilean and Argentine specimens identified as D. ancylus or Diaspidiotus sp. in major collections in Chile, France, Argentina, and United States, and we determine that nearly all of them belong to C. patagonensis and none belong to D. ancylus. Here we provide a redescription of C. patagonensis with a distribution map and a guide to distinguishing it from D. ancylus. Clavaspis patagonensis occurs throughout most of Chile, from Atacama to Aysén, and in at least 3 provinces in Argentina (Neuquen, Rio Negro, Entre Rios). Diaspidiotus ancylus apparently does not occur in Chile. We have examined specimens of C. patagonensis from 18 plant families. Field surveys of diaspidids in Chile indicate that C. patagonensis is one of the most common species of diaspidids in the country.